ALTERATION OF PROTEIN LEVEL IN LAYING RATIONS AT VARIOUS STAGES WITHIN THE LAYING CYCLE AND ITS EFFECT UPON PERFORMANCE OF LAYING HENS

Abstract

An experiment was conducted in which protein level was changed at 84-day intervals throughout the laying year. The diets used contained 11, 15, and 19% protein and these were fed in various sequences during three 84-day periods. All birds received the 15% protein diet in the fourth period. Each of six treatment sequences was imposed upon 160 layers in four replicate pens. The various "step-up" and "step-down" programs had no significant effect upon egg production or feed consumption when compared on a full year basis with a 15% ration fed throughout the year. The 11% protein diet caused a decrease in egg production, egg weight, body weight, and feed consumption in any period in which it was fed but the birds tended to compensate in periods following those in which the low level of protein was fed.There were no differences in performance between the 15 and 19% protein diets and abrupt changes in protein level as such had no adverse effect upon the birds.